Gebhard Schertler (IMAGE) Paul Scherrer Institute Caption Gebhard Schertler, head of PSI’s Biology and Chemistry Research Division. Also shown in the picture is the molecule retinal, which changes its shape when light enters our eye and thus sets the visual process in motion. Credit Scanderbeg Sauer Photography Usage Restrictions PSI provides image and/or video material free of charge for media coverage of the content of the above text. Use of this material for other purposes is not permitted. This also includes the transfer of the image and video material into databases as well as sale by third parties. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.